Electric switch



Patented Jan. 31, 1928.

UNITED STATES SHERROI) E. SKINNER, OF NEW BRITAIN, CONNECTICUT,

FRABY & CLARK COMPANY, OF NEW BRITAIN,

CONNECTICUT.

ASSIGNOR TO THE LANDERS, CONNECTICUT, LA CORPORATION OF ntncrnrc swrron...

Application filed .Tune 18, 1923. Serial No. 648,064.

This invention relates to electrical switches, and has particular reference to switches of that type having a plurahty of terminals and means for electrically connect-- ing the terminals in various combinations.

The object of the invention is to provide a of novelty and advantage, and which isparticularly characterized by its extreme simplicity in construction, the cheapne'ss with.

which it may be manufactured, andthe ease with which it may be assembled and operated.

My improved switch, while having general 1 application, is more particularly adapted for use in combination'with aheating pad of the sort having electrical heating means arranged to give different heats for instance, low, medium and high heats. 4

Other obj ects and advantages of the invention will be obvious and in part pointed out hereafter.

The invention accordingly consists in the features of construction, combinations of elements and arrangement of parts which will be exemplified in the construction hereinafter set forth, and the scope of the application of which will be indicated in the appended claims.

In the drawing forming a part of this specification and in which similar reference characters refer to similar parts,

Figure 1 is a plan view of a switch constructed in accordance with the practice of 85 the invention, the cover or protecting casing being removed to show the arrangement of the working parts.

Figure 2 is a sectional view taken along the line 22 of Figure 1, the covers being shown in section along the diameter perpendicular to the direction of view.

Figure 3 is a diagrammatic view showing of the manner in which a plurality of electrical units, such as those included in an electrical heating pad, may be associated with the switch shown in Figure 1.

Referring to the drawings, and more particularly to Figures 1 and 2, the switch comprises a base, circular or of any desired form as indicated at 1-0, upon which there are mounted a plurality of contacts, 11, 12,13, 14 and 15 preferably disposed equi-distantly irom'the center of the base, and arranged to be engaged selectively by a movable member edge of the base such as a pivoted arm 16 rotatable on a stud 17 which also performs. the function of a binding post for attachment with a source ofcurrent.

Certain of the contacts, such as 11 and 15, may if desired, be merely dummy or dead contacts, so to speak, and not intended to switch of this type having various :teaturesv complete circuits. It will be .noted that these two contacts are the end contacts of the progressive arrangement. It has been found desirable to arrange the contacts in this manner sothat when using the switch the operator may be certain that the current is disconnected trom the associated apparatus when the arm 16 is thrown in either of its extreme positions. All the intermediate contacts 12, 13 and 14: provide positions for the arm 16 at which circuits are completed. In case the circuits to be associated with-the switch are those of a heating pad, for instance, these positions may indicate the low, medium and high heats. 1

Each of the contacts 12, 13 and 14 is provided with a shank as at 18, which extends through to the opposite side of the base 10,

being threaded at the end and having a nut,

as at 19, to form a binding post by means of which they may be connected to respective circuits with which they are associated.

The arm lt-being pivotally mounted on the stud 17 is provided with a suitable bear:

ing as, for instance, a washer 20 interposed between it and the base, stud 17 for holding the stud 17 is suficiently postfor a conductor source of current. The arm 16 is made preferably of metal and is flexible so as to bear resiliently againstthe contacts. A suitable depression, as at 22, may be. pressed from the lower face of the arm to trictionally hold the arm against rotation when in engagement with any one of the contacts. The arm at itsswinging end is preferably bent at right angles to the main body and over the 10 there being a suitable knob or handle 23 of insulating material provided by means of which the arm. is ro tated by the person operating the switch.

Another wire from the source of current and a nut 21'on the arm thereon. The long to form a binding leading from a suitable may be connected to a binding post 2 posts 24 and 25 may by a fuse such as is indicated at 26, extendingthrough a hole 27 bored through the base between the two posts.

As has been before stated, the switch is adapted to connect a suitable source of current selectively with a plurality of electricalunits. In' Fig. 3 there is shown a dia-. gram of. a heating pad which comprises two circuits 30 and 31, eagh of high resistance,

' so as to produce the desired heat, the circuit gether,

'25 and thence througlh t ing ,switch thecircuits and 31 are adapted to be connected with the source of current through the arm .16, either individually or in parallel. To this end certain of the contacts are bridged together and a supplemental contact is provided associated with one of thebridged contacts and adapted to contact a with the arm 16 at the time when the arm is contacting with one of the bridged contacts. In this embodiment the contact 12 is permanently brid ed to the contact 14 through the medium oi? a jumper or strap 35 so that when'the arm is in engagement with either the contact 12 or the contact 14, the current will flow through the circuit 30. The supplemental contact consists of asprin 36 or sultable resilient member extending iagonally as shown in Fig.- 1 from under the head of the contact 13, to a position where it will engage the arm 16 simultaneously as the arm engages the contact 14. To permit this operation the spring 36 is bent up toward its end as at 37 to extend into the path of the arm 16. A suitable hole or depression 38 is provided in the base beneath the'end of the spring 36 so as to permit the end of this spring to be pressed down a suitable distance, and also to, permit free action.

From the above described construction it will be seen than when the arm 16 is in engagement with the contact 14 the spring or supplemental contact 36 is also in engagement with completed through the unit 31, as wellas through the unit 30, the two being connected in parallel at this position of the arm. Therefore, under these conditions and in this position of the arm 16, the greatest available heat will be produced in the' heating pad, 'since' the two circuits are both connected with the sourceof current.

be connected together.

the arm by which a circuit is From the above it will be seen that the switch has five positions, the first and lafi being ofl' positions,and second, third and fourth being low, 'medium and high respectively, it being understood that these positions correspond to the consecutive positionswhich the arm assumes when in engagement with the contacts 11, 12, 13, 14

and '15 in the given order.

' The source of current 18 not-shown in the drawing, it being understood that any suitable means for producing electric current may, be connectedwith the apparatus above.

described through the medium of suitable conductors 40 and 41. Suitable covers 42 may be providedeto protect the parts on each side of the base. These covers may beheld in place by bolts extending through the base at the holes '43. To accommodate conductors leading to and from the switch there is formed a centrally located aperture in each cover.

Thus by the above described construction are accomplished, among others, the objects herelnbefore referred to.

As many changes could be made in the above construction and many apparently widely different embodiments of this inven tion could be made without departing from the scope thereof, it is intended that all matter contained, in the above descriptioni or shown in the accompanying drawing shall be interpretated as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all ofthe generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention: I z

1. An electric switch comprising a plurality of fixed immovable and rigid contacts} a pivoted arm arranged to selectively en gage with said fixed contacts, a bridge between two of said contacts, and a supplemental spring contact connected with the 'unbridged contact and arranged to be directly engaged by said arm simultaneously with one of said bridged contacts. 7

2. An electric switch.comprising a base, three immovable fixed contacts thereon, a fixed bridge connecting two of said contacts, a pivoted arm on said base and arranged to selectively engage said contacts, and a spring having one end connected to the unbridged contact and its other end extending into the path of movement of said pivoted arm, the free end of said spring and one of said bridged contacts being simultaneously directly engageable with said pivoted arm substantially as described.

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